In recent years, liquid crystal displays (LCD) have been put in such an expansive use as to be applied not only to monitors of notebook PCs but also to monitors of desktop PCs and home television sets. Such LCDs use so-called light diffusing plates for scattering light from backlights. For bottom-emitting-type backlights installed in, for instance, home television sets having approximately 20-inch screen size, which are particularly demanded to have higher luminance, light diffusing plates (thickness: 1 to 3 mm) made of acrylic resin have been typically used. However, acrylic resins are dimensionally less stable due to their lower heat resistance and higher hygroscopicity, so that plates made of acrylic resin may be deformed to warp when applied in apparatus of large screen size.
In view of the above, aromatic polycarbonate resins (hereinafter called as “aromatic PC resins” or simply as “PC resins”), which are more excellent than acrylic resins in heat resistance and hygroscopicity, have been used as matrix resins for light-diffusing plates, and demands for such aromatic polycarbonate resins are on increase.
In recent years, light diffusing plates have been manufactured by injection molding in place of traditional extrusion molding (e.g., patent documents 1 and 2). It is because light-diffusing plates (i.e., molding products) molded by injection molding are more excellent in dimensional accuracy and also because higher productivity of injection molding can reduce cost of outer-profile processing.
Patent Document 1: JP-A-11-158364
Patent Document 2: JP-A-10-073725